Methane conversion and hydrogen production over TiO2/WO3/Pt heterojunction photocatalysts

Abstract

Along with the advantages of mild reaction conditions, simple operation, and low energy consumption, the photocatalytic conversion of methane in the presence of water presents great potential in facilitating direct methane conversion into value-added chemicals and H-2 generation. In this work, TiO2/WO3 heterojunction photocatalysts modified with Pt nanoparticles were synthesized and their performances towards methane conversion into ethane (C2H6) and hydrogen (H-2) in the presence of water were evaluated. The ternary photocatalysts were characterized by X-ray diffraction, UV-vis, scanning and transmission electron microscopy and X-ray photoelectron spectroscopy. The highly active TiO2/WO3/Pt photocatalyst achieved C2H6 and H-2 production rates of 1.18 mmol g(-1) h(-1) and 57 mmol g(-1) h(-1), respectively. These values were 37% (for C2H6) and 34% (for H-2) higher than those produced by a TiO2/Pt photocatalyst. The results show that the presence of WO3 in a very small concentration on TiO2 with the introduction of Pt as a co-catalyst contributes to achieving higher activities towards both C2H6 and H-2 evolution.